9Ballr,
Not sure why you got these not particularly helpful answers so far. (edit...I guess I only read the first couple) Here's the deal. I have a 314-3. I have shot with a Z3 and Vantage. When Predator uses the term "accuracy", what they mean is "low squirt". My experience says that the amount of deflection (squirt) you get with the 314-3 is *slightly* more than with the Z3 or Vantage. At most slower to medium speeds, the Z3 has ridiculously low squirt. The 314-3 is pretty good here but not quite as low as the Z. At higher speeds the 314-3 deflects noticeably more, as does the Z. The Vantage, however, is pretty consistent at all speeds. I will say that the Vantage is pretty impressive in that you can hammer a ball with english and the squirt is still quite low. So if what I said here matches what Predator's marketing says, then YES, there is something to their claim.
NOW, that being said, squirt characteristics are but one factor in selecting the right shaft for you. Feel and taper is pretty important for me. In my opinion, the 314-3 has the nicest hit of the 3. The taper is a really long pro taper, which I like. I am tall and use a long bridge. The Z3 and the Vantage have almost the same taper, except the Z is smaller diameter. Both have a conical taper. I personally don't really like a conical taper. Both have a very gradual taper, so even if you don't like conical, it's not *that* bad. The Vantage definitely feels BIG. Even though it is only a little bigger than the 314-3, it feels bigger because of the taper. The Vantage plays super stiff as a result of the size and taper. All the 3 series are on the stiff side, but the Vantage is the stiffest.
For me, a small diameter shaft is something I moved away from a couple of years ago. If you like small diameter, go with the Z. You could even try the S-Tuned Z3 from Seyberts (which has the taper modified to be a pro taper). This way it is small, but non-conical taper. I've heard the squirt on this is crazy low, but that the shaft feels a bit whippy.
For larger diameter, I don't think you could go very wrong with either the 314-3 or the Vantage. I suppose if you don't mind the conical taper, I'd do the Vantage. For me, the 314-3 is the best because of the taper and the hit.
Hope this helps,
KMRUNOUT